Identifying the Critical Supply Chains for Black Carbon and CO[sub.2] in the Sichuan Urban Agglomeration of Southwest China

• Published in: Sustainability 2023-10, Vol.15 (21)
• Main Authors: Li, Shuangzhi, Zhang, Xiaoling, Deng, Zhongci, Liu, Xiaokang, Yang, Ruoou, Yin, Lihao
• Format: Article
• Language: English
• Subjects: Air quality management; Combustion; Energy minerals; Fossil fuels; Global temperature changes
• ISSN: 2071-1050; 2071-1050
• DOI: 10.3390/su152115465

Black carbon (BC) and CO[sub.2] emissions are the two major factors responsible for global climate change and the associated health risks. Quantifying the impact of economic activities in urban agglomerations on BC and CO[sub.2] emissions is essential for finding a balance between climate change mitigation and pollution reduction. In this study, we utilized a city-level environmental extended multi-regional input–output model (EE-MRIO), integrated nexus strength (INS), and structural path analysis (SPA) to quantify the BC and CO[sub.2] footprints, nexus nodes, and supply chains of 21 cities in the Sichuan urban agglomeration (SUA) from 2012 to 2017. The results revealed that approximately 70% of the BC and CO[sub.2] footprints come from inter-city transactions, with Chengdu being the largest importing city, while the supply of other cities was greater than their consumption. The SUA has transitioned from a supply-side city cluster to a consumption-oriented city cluster in its trade with other domestic regions. The SPA analysis highlighted that the construction sector was the largest emitter of downstream BC and CO[sub.2], while the electricity supply, metal/nonmetallic manufacture, oil refining and coking, transportation, and extraction industry sectors were the main nexus nodes for BC and CO[sub.2] emissions in the SUA. Notably, the reduction in BC emissions was due to decreased indirect emissions from oil refining and coking, while the decrease in CO[sub.2] emissions was a result of reduced indirect emissions from electricity supply. This article presents, for the first time, a quantification of the heterogeneous impacts and emission supply chains of BC and CO[sub.2] emissions from economic activities in the SUA, providing valuable insights for developing climate mitigation policies tailored to different urban clusters.